Refrigerating apparatus with defrosting mechanism



w. a. DmsY' 2,624,179

REFRIGERATING APPARATUS WITH DEFROSTING MECHANISM Jan. 6, 1953 Filed Aug. 51. 1949 IN VEN TOR.

Patented Jan. 6, 1953 UNITED ES PATENT o-Frice REFRIGER TING APPARATUS WITH nnrnosrmo MECHANISM William: E; Daisy, Woburn}, Mass; Aii'plicationv August 31, 1949', SeriaYNo. 1131375 screams.

This invention relatesto a refrigerating apparatus with defrostingmechanisma r I The principal object of myinvention is to provide mechanism that will rapidly defrost refrigerating apparatus, yet is simple' in operation; and inexpensive to manufacture and" incorporate in the refrigerating system of said apparatus.

Another object is to provide such nechanism that is compact and unitary so that it requires little or no extra space, nor extramaterials for defrosting, and no preliminary accumulation of heat for later useindefrosting. I r

The foregoing and other objects which will appear as the nature of the invention is better understood, may be accomplished by a construction, combination and operative arrangement of parts such as is disclosed by the drawings and specification. The nature of the invention is such as to render it susceptible to various changes and modifications, and; therefore, I am not to be limited to said disclosure; but am entitled to all. such changes therefrom as fall within the scope of my claims.

In the drawings:

The single figure represents a somewhat-diagrammatic, elevational view of my refrigerating apparatus.

As illustrated, my apparatus'ha's the usual receiver it that contains any well known" liquid refrigerant which passes therefrom through a conduit 2 to a thermostatic expansion valve M such as normally is used in-refrigerating systems and thence to an evaporator [6 of the usual type which may be the still air or forced air type. Various types of well known expansion valves may be used.

From the evaporator IS the refrigerant enters a conduit l8 connected to which is a suction throttle valve 2!) which normally limits the pressure on the suction or intake side of the compressor. This valve 28 sometimes is called a starting load regulator valve, and includes an auxiliary constrictor valve portion or by-pass 22 of the adjustable, needle type which ordinarily is formed within the valve housing, hence only one valve is here needed as constrictor valve portion 22 is always open. However, an external by-pass may be provided outside the housin of said suction throttle valve 29.

Said conduit l8 continues to a circulatory member in the form of an extension coil 24, preferably of the finned tube type, properly sized for minimum drop in pressure, which becomes part of the suction line and which is preferably directly opposite a condenser 36 later explained.

A' conduit 25-continues the system to a compressor 2B of the usual typefor compressing refrigerant' vapor, onwhich afan- 28 isshown mounted and that usually is electrically driven. This fancould be located elsewhere since it is at the exterior of the refrigerating system:

A conduit 32 extends'f'rom said compressor 26 to a well known Venturi' 36 which acts as a siphon; hence is preferred but not indispensable in this refrigerating apparatus, and from there to the usual condensertii and thencetosaidreceiver it.

Connected to and; extending beyond-1 said coir duit 32 and said Venturi 34 if used; a conduit 33 having a well known valve 39" for control of hot gas that is normally closed; Said conduit 33 continues and communicates with said evaporator 1'6. 7

In the normal operation of this system said hot gas valve 39 is closed and the refrigerant, under pressure, passes from said receiver I!) through conduit l2 and expansion valve M to said evaporatorit where the cold refrigerant normally withdraws some heat from and cools the surrounding" air and thence passes through said conduit I8 to said suction throttlevalve" 20, including constrictor valveportion 22, thence through said coil 2tand conduit 25 to said compressor 26. From there it. passesthrough' said conduit 32 to" said Venturi' and said condenser 38 where it is cooled by air drawn over said condenser by said fan 28, thereby ordinarily returning to said receiver It as a liquid.

To defrost said evaporator [6 said hot gas valve 39 is opened and being above said condenser, the refrigerant gas from said compressor 26 flows through Venturi 34 to conduit 38 to said evaporator l6 and since the gas is hot it causes melting or defrosting there. From there the refrigerant, which now may be partly liquid and partly gas, flows only through said by-pass valve 22 since the suction throttle valve portion has automatically closed due to the rise in pressure caused by the hot refrigerant, so it now is serving as an expansion valve. The refrigerant slowly passes through the constrictor or needle by-pass valve portion 22 and from there through conduit I8 to said extension coil 24 where the air is drawn by said fan 28 over said coil 24 to thereby evaporate large quantities of the refrigerant. From there it flows through conduit 25 to compressor 26 to complete the defrosting cycle. As long as said hot gas valve 39 is open the refrigerant hot gas from the compressor 26 will flow to said evaporator lt which thereby functions as a condenser because the hot gasses give up some of their heat to the frost or ice at the outside there.

To restore the normal refrigerating cycle said hot gas valve 39 is closed.

This refrigerating mechanism is adapted for large installations, and also is especially useful in retail market, delicatessen stores and other places where installations of moderate size are used with air-cooled condensers and where merchandise is kept at freezing temperature or below. It is applicable to both forced air and still air evaporators, and can be used on large central station plants.

What I claim is:

1. Refrigerating apparatus comprising a receiver for a refrigerant, an expansion valve, an

evaporator, a suction throttle valve embodying an auxiliary constrictor valve portion, said suction throttle valve being adapted to be closed at a predetermined rise in pressure, while said constrictor valve portion remains open, an extension circulatory member outside the refrigerated space, a compressor, a Venturi, a condenser, conduits in communication respectively with said receiver, expansion valve, evaporator, suction throttle valve, auxiliary constrictor valve portion, extension circulatory member, compressor, Venturi and condenser, whereby a refrigerant may flow therethrough to make a complete refrigerating cycle, a valve to control the flow of gas closed normally, and a conduit extending between and in communication with said gas valve and said Venturi at one side and in communication with said gas valve and evaporator at the opposite side, said Venturi serving as a siphon to maintain flow of said refrigerant from said condenser and receiver to said evaporator and return when said gas valve is open during the defrosting operation.

2. Refrigerating apparatus comprising a receiver for a, refrigerant, an expansion valve, an evaporator, a suction throttle valve embodying an auxiliary constrictor valve portion, said suction throttle valve being adapted to be closed at a predetermined rise in pressure, while said constrictor valve portion remains open, an extension coil outside the refrigerated space, a compressor, a Venturi above said compressor, a condenser, conduits in communication respectively with said receiver, expansion valve, evaporator, suction throttle valve and auxiliary constrictor valve portion, extension coil, compressor,

Venturi and condenser, whereby a refrigerant may flow thcrethrough to make a complete refrigerating cycle, a valve to control the flow of gas closed normally, and a conduit extending between and in communication with said gas valve and said Venturi at one side and in communication with said gas valve and evaporator at the opposite side, said latter-mentioned conduit and valve being above said condenser and said receiver, said Venturi serving as a siphon to maintain flow of said refrigerant from said condenser and receiver to said evaporator and return when said gas valve is open during the defrosting op eration.

'3. Refrigerating apparatus comprising a receiver for a refrigerant, an expansion valve, an evaporator, a suction throttle valve embodying an auxiliary constrictor valve portion, said suction throttle valve being adapted to be closed at a predetermined rise in pressure, while said constrictor valve portion remains open, a compressor, a Venturi, a condenser, conduits in communication respectively with said receiver, expansion valve, evaporator, suction throttle valve, auxiliary constrictor valve portion, compressor, Venturi and condenser, whereby a refrigerant may flow therethrough to make a complete refrigerating cycle, a valve to control the flow of gas closed normally, and a conduit extending between and in communication with said gas valve and said Venturi at one side and in communication with said gas valve and evaporator at the opposite side, said Venturi serving as a siphon to maintain flow of said refrigerant from said condenser and receiver to said evaporator and return when said gas valve is open during the defrosting operation.

WILLIAM E. DAISY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,123,021 Phillips July 5, 1938 2,195,781 Newton Apr. 2, 1940 2,336,735 Jones Dec. 14, 1943 2,433,574 Newton Dec. 30, 1947 2,451,385 Groat Oct. 12, 1948 2,530,440 Nussbaum Nov. 21, 1950 2,555,161 Smith May 29, 1951 

